As disclosed, for example, in non-patent document 1, a molded material including a tubular body and a flange formed at an end portion of the body is produced by performing a drawing process. The drawing process forms the body by drawing a base metal sheet, so that the thickness of the body is lower than that of the base sheet. On the other hand, a region of the metal sheet corresponding to the flange shrinks as a whole in response to the formation of the body, so that the thickness of the flange is higher than that of the base sheet. Hereinafter, the base material may be referred to as a “blank”.
The molded material as described above may be used as a motor case disclosed, for example, in patent document 1 as described below. In this case, the body is expected to function as a shielding material for preventing magnetic leakage to the outside of the motor case. Depending on motor structures, the body is also expected to function as a back yoke of a stator. The performance of the body as the shield material or back yoke is improved as the thickness of the body increases. Therefore, when a molded material is produced by drawing, as described above, a base metal sheet with a thickness larger than the required thickness of the body is selected taking into account the reduction in thickness of the body caused by the drawing process. Meanwhile, the flange is often used for mounting the motor case on a mounting object. Therefore, the flange is expected to have a certain strength.